Duke Energy gave far more money to Republicans than to Democrats in 2013 as environmental groups threatened lawsuits over its coal ash, a campaign watchdog group said Friday.

Democracy North Carolina said three contributions were made shortly after environmental groups threatened to sue Duke.

For the year, it said, Duke’s corporate and political-action committee contributions to Republican politicians and groups totaled $437,000 and Democratic giving $227,000.

The election reform group suggested a “cozy relationship” between Duke and Gov. Pat McCrory, a former employee, resulted in soft regulatory treatment of Duke.

Duke responded that it donates to both parties, often in cycles in which one gets more money than the other, and relates to McCrory as it did his predecessors.

McCrory’s press office didn’t reply to a request for comment. The governor grew heated when asked about his ties to Duke at a news conference Friday.

Democracy North Carolina released the contribution figures as Duke and DENR got subpoenas this week for a federal criminal investigation of a Feb. 2 ash spill on the Dan River.

“Political corruption needs to be a part of the investigation,” said executive director Bob Hall. “What we need to know about the cozy relationship between McCrory and Duke is disturbing and what we don’t know needs to come out in the open.”

The N.C. Department of Environment and Natural Resources, headed by a McCrory appointee, filed a series of lawsuits against Duke after the environmental groups gave notice they would sue over ash contamination.

The department and Duke proposed a settlement in one of those cases, involving the Riverbend power plant west of Charlotte and the Asheville plant. Nearly 5,000 public comments opposed the agreement as too lenient.

DENR spokesman Drew Elliot said McCrory’s office had no influence on its ash oversight.

“We are confident that every action DENR has taken has been for the right reasons, for the protection of the environment,” Elliot said. “We have received no interference or direction from the governor’s office in any of our dealings with Duke Energy in regard to coal ash or anything else.

“Anybody who says different better have the facts to back it up.”

The contributions Democracy North Carolina reported included donations by Duke’s PAC to North Carolina politicians and corporate contributions to national committees that support legislative and gubernatorial campaigns.

The group pointed to “an eerie coincidence” among three Duke contributions and threatened lawsuits last year:

A $4,000 Duke contribution to the Pat McCrory Committee two weeks after environmental groups announced their intention to sue Duke; $100,000 to the Republican Governors Association less than a month after a second notice of an impending lawsuit; and another $175,000 to the Republican Governors Association after environmental groups sued Duke over its Sutton power plant near Wilmington.

Duke spokesman Tom Williams said the company’s PAC gives money to both political parties. One party might get more than another based on election cycles, which party is in power, individual candidates and other factors, he said.

“The PAC board makes its own decisions,” he said. “They don’t make decisions based on single issues. ... The PAC does not make decisions on when we’re being sued by individual groups.”

Duke took public heat for extending, and later paying for, a $10 million line of credit for Charlotte to host the 2012 Democratic National Committee, Williams noted.

Williams said its relationship with DENR is similar to that with regulators in the other five states in its territory.

“We certainly talk to the governor’s office, as we did with (former Gov. Mike) Easley’s office or Bev Perdue’s,” he said. “We’ve always been in touch with the governor’s office.”

McCrory grew irritated at a news conference Friday on this week’s winter storm when asked about his ties to Duke, WRAL.com in Raleigh reported.

The governor said he had “had no conversations with Duke Energy about the lawsuits or about the federal action,” the website said.

Asked whether his ownership of Duke stock creates the appearance of a conflict of interest, McCrory said: “In my 14 years as mayor of Charlotte and my one year as governor, I separate my job as governor, and I’m very proud of the job we’ve done as governor, and that regards to any company in North Carolina.”